/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.visitor;

import proguard.classfile.*;
import proguard.util.*;

import java.util.List;

/**
 * This <code>MemberVisitor</code> delegates its visits to another given <code>MemberVisitor</code>, but only when the
 * visited member has a descriptor that matches a given regular expression.
 *
 * @author Eric Lafortune
 */
public class MemberDescriptorFilter implements MemberVisitor {
    private final StringMatcher regularExpressionMatcher;
    private final MemberVisitor memberVisitor;

    /**
     * Creates a new MemberDescriptorFilter.
     * 
     * @param regularExpression the regular expression against which member descriptors will be matched.
     * @param memberVisitor the <code>MemberVisitor</code> to which visits will be delegated.
     */
    public MemberDescriptorFilter(String regularExpression, MemberVisitor memberVisitor) {
        this(regularExpression, null, memberVisitor);
    }

    /**
     * Creates a new MemberDescriptorFilter.
     * 
     * @param regularExpression the regular expression against which member descriptors will be matched.
     * @param variableStringMatchers an optional mutable list of VariableStringMatcher instances that match the
     *        wildcards.
     * @param memberVisitor the <code>MemberVisitor</code> to which visits will be delegated.
     */
    public MemberDescriptorFilter(String regularExpression, List variableStringMatchers, MemberVisitor memberVisitor) {
        this(new ListParser(new ClassNameParser(variableStringMatchers)).parse(regularExpression), memberVisitor);
    }

    /**
     * Creates a new MemberDescriptorFilter.
     * 
     * @param regularExpressionMatcher the regular expression against which member descriptors will be matched.
     * @param memberVisitor the <code>MemberVisitor</code> to which visits will be delegated.
     */
    public MemberDescriptorFilter(StringMatcher regularExpressionMatcher, MemberVisitor memberVisitor) {
        this.regularExpressionMatcher = regularExpressionMatcher;
        this.memberVisitor = memberVisitor;
    }

    // Implementations for MemberVisitor.

    public void visitProgramField(ProgramClass programClass, ProgramField programField) {
        if (accepted(programField.getDescriptor(programClass))) {
            memberVisitor.visitProgramField(programClass, programField);
        }
    }

    public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod) {
        if (accepted(programMethod.getDescriptor(programClass))) {
            memberVisitor.visitProgramMethod(programClass, programMethod);
        }
    }

    public void visitLibraryField(LibraryClass libraryClass, LibraryField libraryField) {
        if (accepted(libraryField.getDescriptor(libraryClass))) {
            memberVisitor.visitLibraryField(libraryClass, libraryField);
        }
    }

    public void visitLibraryMethod(LibraryClass libraryClass, LibraryMethod libraryMethod) {
        if (accepted(libraryMethod.getDescriptor(libraryClass))) {
            memberVisitor.visitLibraryMethod(libraryClass, libraryMethod);
        }
    }

    // Small utility methods.

    private boolean accepted(String name) {
        return regularExpressionMatcher.matches(name);
    }
}
